1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Jobisdone [24]
3 years ago
13

Is a candle melting in the hot sun a chemical or a physical change?

Chemistry
1 answer:
alukav5142 [94]3 years ago
4 0
Chemical,  because it is breaking down the chemical and properties in the candle itself.
You might be interested in
A cat travels 240 meters in 30 seconds, and a sprinter travels 100 meters in 9.5 seconds. Which is traveling faster, the cat or
joja [24]

Answer:

The cat

Explanation:

1) You need to find how many meters per second each thing is sprinting, so you can divide the meters by seconds for each.

\frac{240}{30} = 8 m/s\\\frac{100}{9.5} = around  10.5 m/s

2) Per second, the sprinter is able to achieve 8 meters, while the cat can do around 10.5 meters. 10.5 is greater than 8, making the cat faster than the sprinter.

4 0
2 years ago
What is the mass of 2.49 cm of aluminum? The density of aluminum is 2.70 g/cm.
OverLord2011 [107]

Answer:

6.723

Explanation:

2.49*2.70

5 0
3 years ago
1 Ammonia, NH3, reacts with incredibly strong bases to produce the amide ion, NH2 -. Ammonia can also react with acids to produc
Charra [1.4K]

Answer:

a) ammonium ion

b) amide ion

Explanation:

The order of decreasing bond angles of the three nitrogen species; ammonium ion, ammonia and amide ion is NH4+ >NH3> NH2-. Next we need to rationalize this order of decreasing bond angles from the valence shell electron pair repulsion (VSEPR) theory perspective.

First we must realize that all three nitrogen species contain a central sp3 hybridized carbon atom. This means that a tetrahedral geometry is ideally expected. Recall that the presence of lone pairs distorts molecular structures from the expected geometry based on VSEPR theory.

The amide ion contains two lone pairs of electrons. Remember that the presence of lone pairs causes greater repulsion than bond pairs on the outermost shell of the central atom. Hence, the amide ion has the least H-N-H bond angle of about 105°.

The ammonia molecule contains one lone pair, the repulsion caused by one lone pair is definitely bless than that caused by two lone pairs of electrons hence the bond angle of the H-N-H bond in ammonia is 107°.

The ammonium ion contains four bond pairs and no lone pair of electrons on the outermost nitrogen atom. Hence we expect a perfect tetrahedron with bond angle of 109°.

5 0
3 years ago
Why is haemoglobin a pure substance
dem82 [27]
<span>Haemoglobin is a pure substance because it contains only one type of atom. </span>
6 0
3 years ago
What is the answer to this question?
lord [1]
The answer is D.

The atomic number stands for the number of protons in each element. The number of protons is what is unique to each element. The number of neutrons varies; this is what isotopes are. The number of protons being the atomic number explains why the atomic number is an identifying characteristic of each element.
8 0
3 years ago
Other questions:
  • The force that pushes electrons through a wire is called gravitational force 1 . Static force 2 magnetic force 3 electrical pote
    15·1 answer
  • The longer the reaction time is, the the reaction rate is. Reaction time is to reaction rate.
    10·2 answers
  • PLEASE HELP!!!
    6·1 answer
  • Given that equation Na+(s)O2–&gt; Na2O. Find the mass of sodium needed to produce 12.5 grams of sodium oxide.
    6·1 answer
  • The balanced net ionic equation for precipitation of CaCO3 when aqueous solutions of Li2CO3 and CaCl2 are mixed is
    13·1 answer
  • As the temperature increases, the molecular motion of the molecules decreases and it
    11·2 answers
  • The following picture would be best described us
    11·1 answer
  • Its Accelerated Science 8th grade​
    9·1 answer
  • Identify the independent /manipulated variable
    11·1 answer
  • Molecular compounds are capable of forming multiple covalent bonds. the compound below that contains a triple bond is:
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!